Discuss what trophic level humans occupy on an ecological pyramid, and explain what happens to contaminants and environmental pollution (such as mercury) as you move down and up the ecological pyramid (what is this called? )

smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. those muscles push materials like food or blood through organs. unlike skeletal muscle, smooth muscle can never be under your control.